Apparatus such as smart tags or labels that can be used in supply chain management of goods are known. Such apparatus may be used to monitor the exposure of sensitive goods to environmental conditions such as temperature variations, ultra violet (UV) radiation, humidity or any other parameters.
The goods may comprise, for example, food products or medicines which may have storage conditions that must be met to ensure they are maintained in a satisfactory condition. For example, when transporting vaccines or other medicines, it is important that they do not get exposed to elevated temperatures which may degrade the efficacy of the medicine.
In order to provide low cost smart tags and labels such apparatus may use chemical or physical processes to provide a visible colour change to a portion of the smart tag or label. The user can then determine whether or not the goods are still in a satisfactory condition by looking at the colour of the label. This enables the smart tags and labels to be simple devices without any electronic components or moving parts. However such smart tags and labels only provide a limited amount of information to the user.
It is advantageous to provide an apparatus which may be configured to provide detailed information about the environmental conditions that the goods have been exposed to.